Metal Sonic is a robotic version of Sonic the Hedgehog, created by Dr. "Eggman" Robotnik to eliminate Sonic, though all attempts have failed. Metal Sonic first appeared in Sonic CD in an attempt by Eggman to alter the past. Since then, Metal Sonic has appeared as a selectable racer in Sonic R, an enemy in Knuckles' Chaotix, a playable character in Sonic Adventure 2 and Sonic Adventure 2:Battle, the main antagonist and final boss ofSonic Heroes, and an unlockable character in Sonic Rivals.
In Super Smash Bros. Brawl
Metal Sonic appears as a sticker. In some cases, one may fight against or can play as the metallic version of Sonic in Brawl, which is introduced as "Metal Sonic" in Classic Mode, although it is not the robot.